Feed spouts for wood chippers



July 31, 1962 s. HANSEL 3,047,244

FEED SPOUTS FOR WOOD CHIPPERS Filed June 20, 1960 l N VEN TOR SYDNE Y HANSEL atent Ofiice 3,047,244 Patented July 31, 1962 FEED SPOUTS FOR WOOD CHIPPERS Sydney Hansel, 980 Cherry St., Edmonds, Wash.

Filed June 20, 1960, Ser. No. 37,126 6 Claims. (Cl. 241278) My invention relates to improvements in feed spouts for wood ehippers.

In the pulp and other industries machines known as chippers are used to reduce logs and other lengths of wood to chip form. One such machine commonly in use is provided with a rotary disc on which a number of knives are mounted and said knives coact with a stationary bed knife to sever chips from a piece of wood stock. The stock is brought up to the machine by means of a conveyor and a feed spout or chute is interposed between the end of the conveyor and the working face of the disc to support the wood length being acted upon by the knives.

' The present invention relates to such a feed spout and an important object is to provide a structure which will ensure a smoother and more eflicient cutting operation than has hitherto been attained with the conventional spout.

A further object of the invention is to provide means whereby the wood is directed towards the bed knife and is buttressed thereby as the stock is engaged by the disc knives.

A still further object is to provide a feed spout which will utilize more of the effective cutting length of each of the disc knives so as to reduce localized wear upon the cutting edge and thus decrease the number of shutdown periods required for and other maintenance.

These and other objects will appear in the following specification and be shown in the accompanying drawings in which:

FIGURE 1 is a plan of a chipper fitted with the invention.

FIGURE 2 is a vertical section taken on the line 22 of FIGURE 1.

FIGURE 3 is an enlarged section taken on the line 33 of FIGURE 2 and also FIGURE 6.

FIGURE 4 is an elevation of the feed spout only as viewed from the line 44 of FIGURES 1 and 6.

FIGURE 5 is a diagrammatic view showing the cutting action of the knives upon a log supported in the feed spout.

FIGURE 6 is a reduced scale elevation of a chipper fitted with a drop feed spout.

In the drawings like characters of reference indicate corresponding parts in each figure.

The chipper indicated generally by the numeral 10 is provided with a base 11 in which a compartment 12 is defined. Mounted on the base is a pair of bearings 14 which journal a horizontal shaft 15. A suitable motor, not shown, is provided to drive the shaft in a clockwise direction, as viewed in FIGURE 2, and secured to said shaft is a heavy disc 17. The disc extends into the cornpartment 12 and its upper segment is enclosed by a casing 18 which is suitably secured to the base 11. On the working face '20 of the rotary disc a number of spaced knives 21 are provided which knives have their cutting edges disposed substantially in the same plane as the cutting edge of a bed knife 22. The bed knife is secured to the front wall 24 of the base 11 so as to extend into one side of an elongated opening 25 formed in said front wall.

The wood chipper 10 is fitted with a feed spout having a horizontal top wall 31, and a vertical side wall 32. The inner end 33 of the feed spout is received within the opening 25 and the spout is bolted to the front wall 24 with its Longitudinal axis disposed at an acute angle to the working face 20, preferably the order of 37% In this position the inner end 33 of the feed spoutis spaced from the disc face 20 and extends parallel thereto as shown clearly in FIGURE 3. 'The inner end 33 has an arcuate lower edge 34 which is a true are struck from the centre of the disc 17 and it will be seen particularly in FIGURE 2, that the lowermost point of the arcuate edge is intersected by the vertical axis of said disc. Beyond its lowermost point, or to the left of the vertical axis of the disc, the edge 34 curves upwardly to a very slight extent to meet the bed knife 22.

As best shown in FIGURE 4, the outer end 36 of the feed spout is rectangular and is provided with a lower or entering edge 37 which is straight and horizontal. Between the edges 34 and 37 the bottom and side of the spout are molded to provide 'acurving surface with the amount of curvature progressively decreasing from the edge 34 to the edge 37. This surfiace of the spout supports the wood being fed to the chipper knives and since it provides a gradual change from a horizontal to a curved spout part it will hereinafter be referred to as the transition surface 38'.

Wood is delivered to the machine by means of a conveyor 40 provided with an endless belt 41. The top run of the conveyor belt is substantially aligned with the edge 37 of the spout and the wood is adapted to move from the conveyor through the feed spout tothe knives.

As a length of wood leaves the conveyor it first comes into contact with the transition surface 38 and is directed thereby towards the side wall 3-2 and the bed knife 22 as it is advanced towards the working face of the rotating disc 17. The disc knives 21 sweep past the inner end 33 along an annular path indicated by the letter X in FIGURE 5 and while so doing remove slices from the end of the wood which is now firmly supported by the bed knife. Since the edge 34 is parallel to the path X, the knives 31 do not cut against this arcuate edge with a scissor like action to the same extent as would occur with the conventional fiat-bottomed spout. The curved edge 34 mainly serves as a guide or support for the Wood which is buttressed by the bed knife against the cutting action of the disc knives. Thus the clearance between the inner end 33 of the feed spout and the working face 20 of the disc may be greater than is normally the case. Less wear takes place on the inner end of the spout and the need for a hardened steel reinforcing strip is eliminated.

It will be noticed, particularly in FIGURE 5, that the shape of the inner end 33 is such that full advantage is taken of the path X swept by the disc knives. If the feed spout was rectangular, or even in the form of a trapezoid throughout its entire length, the cross sectional area of the spout would have to be considerably smaller than in the present case.

The feed spout has been described as a horizontal member but it will be understood that in some wood chipper installations it may conveniently be disposed in a plane other than a horizontal one. For example as shown in FIGURE 6, some shippers are fitted with a drop feed spout 45 viz. the wood to be cut into chips is dropped into the spout from the delivery end of the conveyor. In such a case the feed spout 45 is constructed in the same manner as the spout 30 and its position in relation to the chipper disc the same. However the spout 45 is rotated about the axis of rotation of the disc so that the outer end is disposed above the inner end of said spout. Obviously the bed knife is also repositioned on the chipper so that its position with respect to the feed spout remains as above described. In other words the cutting edge of the bed knife extends along a the inner end of the side wall 32 of the feed spout in the manner shown in FIGURE 3.

What I claim as my invention is:

1. In a chipper having a rotary disc fitted with knives, said disc knives having cutting edges uniformly spaced away from the plane of the disc and a coacting bed knife having a straight cutting edge, a feed spout comprising a tubular member extending into the chipper adjacent to the bed knife, said member having an inner end and an outer end, said inner end being disposed in a plane substantially parallel to the plane of the disc and to the cutting edge of the bed knife, said member having a flat side wall disposed parallel to the straight cutting edge of the bed knife, a top wall disposed substantially at right angles to the side wall and a curved wall connecting the side and top walls, the radius of curvature of the curved wall progressively decreasing from the inner end to the outer end of the tubular member.

2. Structure as claimed in claim 1, wherein the side wall is disposed at an acute angle to the axis of rotation of the disc.

3. Structure as claimed in claim 1, wherein the side wall is disposed at an acute angle to the axis of rotation of the disc and the outer end of the tubular member is higher than the inner end of said member.

4. Structure as claimed in claim 1, wherein the curved wall, adjoining the inner end of the tubular member, is curved about a radius struck from the center of the rotary disc.

5. Structure as claimed in claim 1, wherein the curved wall, adjoining the inner end of the tubular member, is curved about a radius struck from the center of the rotary disc and is disposed within the arcuate path of travel of the radially outermost portions of the bed knives.

6. Structure as claimed in claim 1, wherein the outer end of the tubular member is substantially rectangular in cross section.

References Cited in the file of this patent UNITED STATES PATENTS 503,599 Heinlein Aug. 22, 1893 775,382 Philbrick Nov. 22, 1904 20 2,420,966 Motz an May 20, 1947 I FOREIGN PATENTS 1,061,910 France Dec. 2, 1953 

